The multiverse is often thought to be speculative account of how one might solve problems in fundamental physics. Yet this kind of speculation seems different from the unrealistic assumptions instrinsic to scientific modelling more generally, e.g. infinite populations of genes in population genetics. This latter kind of modelling can be further distinguished from the construction of fictional or toy models. I discuss these different modelling practices and the nature of speculation associated with each, showing why the “models as fictions” view not only fails to capture the subtleties in modelling strategies but undermines the larger goals of modelling as a scientific activity.